沙尘暴中毫米波传播衰减及双频互相关函数研究

对毫米波在沙尘暴中的衰减和双频互相关函数（Γ）进行了研究.根据沙尘粒子尺度的对数正态分布,应用Mie理论和粒子介电常数等效的方法,对不同水含量的沙尘暴引起毫米波的衰减进行了研究;在考虑粒子尺度分布和等效介电常数时,应用分析和傅里叶变化方法求解Γ的微分方程,对其解进行数值分析,研究不同水含量的沙尘暴对Γ的影响.结果表明,当水含量大于1.00%时,衰减会显著增加;一般仅对10 GHz以下电波的衰减才可忽略.对Γ的影响,在100 GHz以下较小,但水分含量变化的影响相对明显;在220 GHz时,对Γ影响显著,但随水含量的变化较小.因此,对于开发和应用较高频段的毫米波信道,沙尘暴对毫米波脉冲的衰减及Γ特性的影响需要考虑.

Research on attenuation and the two-frequency mutual coherence function for millimeter wave propagation in the sand and dust storm

The attenuation and the two-frequency mutual coherence function (Γ) for millimeter wave propagation in the sand and dust storm are studied. According to the log-normal size distribution of the sand particles, the millimeter wave attenuations induced by the sand and dust storm of different water contents are studied by the Mie theory and the effective permittivity method. On considering particles size distribution and effective permittivity, the Γ differential equation is solved using the analysis and Fourier transform technique. The Γ solution is numerically analyzed. The influence of the sand and dust storm for different water contents on Γ is studied. It is shown that the attenuation evidently increases with the water content in sand particles increasing, when the water content is over 1.00％. Generally, the attenuation can only be neglected for the electromagnetic wave frequency below 10GHz. The influence of the sand and dust storm on Γ is smaller below 100GHz, but the influence of the water content change on Γ is relatively obvious. At 220GHz, the influence on Γ is apparent, but the change of the influence is small with the change of the water content. Therefore, for the exploitation and application channel of higher millimeter wave band, the attenuation and the influence on Γ induced by the sand and dust storm need be considered.